The present invention relates generally to a self-erecting structure. In particular the invention relates to a multi-purpose, self-erecting, tent-like structure which has advanced insect protection characteristics and which is specifically adapted for use in both field operations and applications in which insect protection is desired. In preferred embodiments of the invention, components are adapted to provide multiple functions whereby the invention is particularly adapted for military applications.
Several types of self-erecting tents and similar structures which rely on two or more springy support loops have heretofore been known. In those structures, the springy support loops were made of a highly resilient material having a good memory. Steel, such as ASTMA 229 steel wire having a range of from 10 gauge to 6 gauge has generally been the material preferably used for forming the support loops in such structures.
U.S. Pat. Nos. 4,458,634 which issued on Aug. 22, 1989, and subsequent Re. 35,571 reissued on Jul. 29, 1997, entitled SELF ERECTING STRUCTURE of E. S. McLeese, the contents of which are herein incorporated by reference, each describe one such structure in which multiple steel loops form the skeletal support framework of a self-erecting tent. As described therein, there are at least two generally elliptical support loops, one of which is a lower support loop configured to lie on the ground, while the other required support loop, referred to herein as the upper support loop is generally xe2x80x9csaddlexe2x80x9d shaped. Consequently, the lower support loop is substantially coplanar, and it is, therefore, particularly well adapted to lie flat on the ground giving the tent stability. On the other hand, the xe2x80x9cendsxe2x80x9d of the ellipse which forms the upper support loop are raised off the ground, thereby providing a skeletal framework which supports the tent""s fabric above the ground.
Similarly, U.S. Pat. No. Des. 341,407, entitled PORTABLE STRUCTURE issued to E. S. McLeese on Nov. 16, 1993, shows a portable structure having a pair of loop-like members, one of which lies flat on the ground, and the other of which provides a skeleton to give vertical support.
U.S. Pat. No. 5,163,461 entitled SELF-ERECTING SHELTER (the contents of which are also incorporated herein by reference), which issued on Nov. 17, 1992 to M. K. Ivanovich, et al. describes a self-erecting structure similar to those described above wherein the resilient support loops are made of a single, continuous length of steel wire.
The McLeese ""634 and ""571 patents, and the Ivanovich, et al. patent each describe the benefits of having the resilient loop structure as providing a tent which is self-erecting and in which the fabric of the structure is permanently attached to the support structure. While these designs are capable of virtually instantaneous erection, when they are folded between uses, (although reasonably flat) they are relatively large in size. Consequently, they cannot readily be carried in a rucksack by a soldier. The reason that they are relatively large in size is that the folding system which is taught is compatible with the material (spring steel) from which their support loops is constructed, and it can be folded down into only three loops. Accordingly, a tent structure suitable for use by only a single soldier, having a typical length of about 86 inches and a typical width of from about 30 inches at one end to about 20 inches at the other end, would have a base periphery of about 222 inches (Those skilled in the art will recognize that due to the ovoid, or elliptical, shape of the base support this xe2x80x9crectangularizationxe2x80x9d of the dimensions is an approximation.). With a base periphery of about 222 inches, when the base is folded into three loops, each loop will have a circumference of about 71 inches, so the three loops which define the size of the stored tent have a diameter of about two feet, which is too large to fit into a soldier""s rucksack. Accordingly, while the self-erection feature of these structures is quite desirable, these patents do not teach any way, or material, which would allow them to be folded into a compact size suitable for military field applications. In fact, they each specifically teach a method of folding the tent for storage which requires that they have three loops. As the actual folding of these structures into three flat loops is itself by no means obvious, the teachings of these patents with respect to the folding of the structures for storage is critical to the other teachings in these patents. This becomes self-evident the first time one removes one of these self-erecting structures from its carrying case, erects it, and then attempts to again store it. In fact, even after the tents of this configuration are folded into their storage configuration, they must be restrained using straps or other means, or they will immediately deploy when released. Thus, while materials other than spring steel, such as fiber composites (e.g., graphite and highly flexible plastics) are discussed in the McLeese patents, and while fiberglass and rattan are discussed in the Ivanovich, et al. patent, there is no teaching in either of these patents of any way to minimize the folded, or xe2x80x9cstoragexe2x80x9d size of the tents. Instead, the McLeese and Ivanovich, et al. patents both teach a storage configuration having three loops along with support materials selected to maximize their self-erection characteristic.
U.S. Pat. No. 5,343,887 entitled SELF-ERECTING PORTABLE FABRIC STRUCTURE, which issued on Sep. 6, 1994 to T. C. Danaher describes an elongated structure which uses a series of collapsible hoops, which are oriented vertically, and which are separated horizontally by a series of horizontal spreader members to form a support structure for a self-erecting tent. Due to the configuration of the elements described in the Danaher patent, the horizontal spreader members present a problem in making the tent either fully self-erecting or compact. While there is description within the Danaher patent with respect to folding the collapsible hoops into as many as nine loops, it is not clear from the disclosure how this would be accomplished or how that would matter, given that the storage size of the tent would ultimately depend, also, on the manner of dealing with the horizontal support member. Further, as the vertical support for the tent is based upon the vertically oriented hoops, and as the tent described by Danaher does not have any structural base (as do the structures shown in the McLeese and Ivanovich, et al. patents described above), it is not clear that the tent described in the Danaher patent would not have a tendency to roll on the ground, particularly if the tent was erected on a slope or if windy conditions prevailed.
Thus, while the prior art tents of McLeese and Ivanovich, et al. provide for a fully self-erecting structure, and while they can be stored in relatively compact carrying cases, they are not truly adapted to be carried by a soldier in a rucksack, and while the tent described by Danaher includes hoops which can be folded into relatively small diameters, the horizontal spreader members of that design create a problem when it comes to storage and erection, and the overall design taught by Danaher fails to provide structure having a truly stable base.
Other structures, such as the ones described in U.S. Pat. No. 3,960,161 entitled PORTABLE STRUCTURE which issued on Jun. 1, 1976 to L. R. Norman or in U.S. Pat. No. 3,990,463 also entitled PORTABLE STRUCTURE and issued on Nov. 9, 1976 to L. R. Norman are described as being capable of both self-erection and small storage, but they lack the structural base member needed to provide a well-defined floor and desirable stability when the structure is erected on sloped surfaces, or in windy conditions.
Issues, in addition to ease of erection and storage, and stability on the ground when erected, must also be dealt with in the design of a truly xe2x80x9cmilitarizedxe2x80x9d protective structure. Thus, the McLeese patents describe different types of webbing, fabric, or tenting materials which may be treated to be suitable for shelter from the elements, or alternatively, to be waterproof, to provide shelter from intense solar radiation, to be insulated and/or reflective, or to prevent the transmission of infrared or other radiation, and/or to inhibit the operation of sensing devices. However, as noted in the McLeese patents, the fact that the fabric is permanently attached to the structural material means that the structure taught therein could exhibit only one of any inconsistent characteristics. Thus, McLeese alternatively teaches a structure which is either waterproof, or comprised of mosquito netting.
Accordingly, while soldiers today may carry both mosquito netting and tent portions (Generally, two soldiers each carry one-half of a military tent, and the two portions are not interchangeable, at that.), they also carry other items, such as rain ponchos, which are not integrated by design. Accordingly, the number of items which they carry, the weight of such items, and an individual soldier""s need to rely upon another soldier having a matching tent portion have not been taken into account by presently deployed equipment. Further, other needs of soldiers, such as the need to provide individualized protection from biting insects, such as mosquitoes, both in the field and in beds or cots in field hospitals, have not been directly addressed by the structures or storage methods taught in the prior art.
In view of the foregoing, it would be desirable to have a self-erecting structure which has been designed to provide adaptability for multiple applications which is designed to be capable of forming a fully integrated military solution.
In accordance with the present invention, a xe2x80x9cmilitarizedxe2x80x9d self-erecting structure and a novel storage method have been designed to provide numerous advantages over the structures and storage methods heretofore known. In particular, the structure of the present invention is self-erecting, and it utilizes a springy skeletal support structure, preferably including a pair of generally elliptical (or ovoid) loops formed of a material which is both resilient and strong. While these features are described in the prior art, the preferred embodiments of the present invention employ a material, such as a vinyl polyester (xe2x80x9cvinylesterxe2x80x9d), or polyester, and fiberglass composition which is created by pulling fiberglass through a high content vinylester, in a process called xe2x80x9cpulltrusionxe2x80x9d. The resilience and strength qualities of the vinylester fiberglass have been optimized to provide both the self-erection feature previously known, and to enable a novel storage method, not previously known, to be employed whereby a tent having the same overall dimensions as those previously known can now be stored in a carrier having approximately one-half the size of those previously known.
In the preferred embodiment of the present invention, the fabric used on the structure includes two portions, each of which has distinct beneficial qualities, in order to optimize the utility of the structure. In particular, in the preferred embodiment of the invention the floor and lower wall portions are preferably made of a waterproof material, whereas the upper portion of the fabric material is a mesh material which provides protection from insect intrusion.
Further benefits provided in preferred embodiments of the invention are provided by additional features, including camouflage printing on the fabric material, pretreatment of the upper fabric with an insecticide and insect repellent, and pretreatment of the floor and lower wall material to make it repellent to water, as well as an insecticide and an insect repellent.
The present invention is further enhanced by the inclusion of integrated straps which provide a means for holding the structure in its stored configuration. In the deployed configuration, the straps are configured to provide a means for attaching the structure to a bed or cot in a field hospital, whereby the structure is usable to provide insect protection to an occupant who is confined in a field hospital.
An additional feature of exemplary embodiments of the present invention is that it has been designed to optionally use a rain fly which can be removed for use as a rain poncho, thereby providing enhanced functionality of the various components which comprise the invention.
Finally, the present invention includes a novel method for providing storage in which both folds and twists are employed. Accordingly, the present invention can readily be folded into a size approximately significantly smaller than was heretofore possible based upon the storage methods and materials previously used. In particular, in accordance with one embodiment of the storage method taught herein, a tent having fabric which is permanently affixed to a support structure can be folded into either four (or even six) loops, rather than the three loops heretofore taught in the prior art for such tent structures. Consequently, a tent made in accordance with the present invention, and folded in accordance with the inventive method, can readily provide shelter for an individual soldier who could carry the tent in a standard rucksack, something not heretofore possible.